Chair or analogous article of furniture

ABSTRACT

A chair or similar article of furniture has a back structure and a seat structure which are hinged together to allow for an adjustment of the inclination of the back structure. The back structure is connected with slides which are carried by a substantially horizontal guide member on each side of the chair. The seat structure is supported at its front end by a supporting structure, and a substantially vertical movement of the line of connection between the back structure and the seat structure is provided for when the inclination of the back structure is adjusted by movement of the slides.

Knutsen States Patent 1 CHAIR OR ANALOGOUS ARTICLE OF FURNITURE [76] Inventor: Odd Knutsen, N-7208 Mageroy,

Norway [22] Filed: Nov. 20, 1973 [21] App]. No.: 401,445

[52] US. Cl 297/320, 297/342, 297/422 [51] Int. Cl. A47c 1/032, A47c 7/54 [58] Field 01 Search 297/282, 294, 320, 323, 297/343, 422, 441, 446, 456

[56] References Cited UNITED STATES PATENTS 2,708,474 5/1955 Lindroth 297/343 3,332,718 7/1967 Adolf 297/294 3,773,383 11/1973 Ekornes 297/320 R24,762 1/1960 Sellner 297/320 FOREIGN PATENTS OR APPLICATIONS 683,718 11/1939 Germany 297/320 Primary Examiner-Casmir A. Nunberg Attorney, Agent, or Firm-Spencer & Kaye [57] ABSTRACT A chair or similar article of furniture has a back structure and a seat structure which are hinged together to allow for an adjustment of the inclination of the back structure. The back structure is connected with slides which are carried by a substantially horizontal guide member on each side of the chair. The seat structure is supported at its front end by .a supporting structure, and a substantially vertical movement of the line of connection between the back structure and the seat structure is provided for when the inclination of the back structure is adjusted by movement of the slides.

15 Claims, 2 Drawing Figures 2 Q gill/Fwy; k I ll H PATENTEB MR] 1 I975 SHKET 1 0F 2 PATENTEB MAR] 1 I975 SHEET 2 or '2 CHAIR OR ANALOGOUS ARTICLE OF FURNITURE BACKGROUND OF THE INVENTION The present invention relates to a chair or an analogous article of furniture, comprising a back structure and a seat structure which are hinged together to allow for an adjustment of the inclination of the back structure, and wherein the back structure is connected with slides which are carried by a substantially horizontal guide member on each side of the chair.

Different chairs with an adjustable inclinable back structure are known. A plurality of demands are however placed on such chairs. They should have a pleasing appearance, be light in weight, be cheap, sturdy and, primarily, provide a comfortable seating position. A particular problem related to low chairs of this kind is the difficulty with which a person has to rise from such a chair, having a very inclined back structure relative to the vertical plane. The back structure will then provide almost no support to the back of the person during the main part of the rising movement. Inversely, when sitting down, the back of the person meets no support until the upper part of the body has leaned back. Thus it is preferable to have a back structure which follows the movement of the person and gives at least a certain support by the movements described.

SUMMARY OF THE INVENTION The main object of the invention is to provide a chair of the described kind, which meets and satisfies these demands.

According to the invention, this may be achieved by a chair of the described kind, wherein the seat structure is supported at its front end by a supporting structure and means are provided to effect a substantially vertical movement of the line of connection between the seat structure and the back structure when the inclination of the back structure is set by movement of the slides.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a side elevational view of a chair according to the invention; and

FIG. 2 is a rear elevational view of the chair shown in FIG. 1.

DESCRIPTION OF THE PREFERRED EMBODIMENT The shown embodiment of a chair according to the invention comprises a base member 11 of steel tubing or a corresponding material, with a U-shaped support member 12 resting on the floor and a supporting column 13 at each ends of the legs of this support member. The support columns 13 each ends in a support arm 14 which is substantially parallel to the legs of the U- shaped support member 12. In each end of the tubing of the base member 11 a solid rod is inserted with close fit. This rod 15 projects from the end of the arm 14, one on each side of the chair. These projecting ends each carry the ends of another U-shaped seat structure support member 16 which is arranged substantially parallel to the support member 12 of the base member 11. This member, which will be termed seat support, is also manufactured of a steel tubing with the same diameter as the steel tube of the base member ll.

The legs 16A of the seat support each carry a pair of slide members 17 and 18 which are mutually connected by a lath 19 of wood or plastic material with suitable rigidity. The slide members 17 and 18 are formed by sleeves 17A and 18A respectively, with bushings of a material with the necessary resistance to wear, e.g. Nylon or Teflon (Trade Mark). Said bushings enclose the legs of the seat support 16 with an appropriate close fit. The sleeves 17A and 18A are secured to the lath 19 with screws through the wall of the sleeves. The sleeves and the bushings may be provided with means (not shown) to adjust the clearance, primarily to compen' sate for wear of the bushings during the chair life.

The back structure comprises a U-shaped frame member 20 which is pivotally mounted on the backward slides 18 with a bolt 22 through a sleeve 21 on each slide. This bolt 22 is rigidly mounted on the adjoining part of the frame member 20 and enables the back structure to pivot about an axis extending through the bolts 22 on opposite sides of the chair, slightly above the adjoining part of the seat structure. As shown particularly in FIG. 1, the frame member 20 is bent according to the back contour of a person.

The seat structure and the back structure further comprises a web 24 of canvas or a similar material, which is suspended between the forward part of the seat support 16 and the top part of the back frame member 20. This web is secured to a rod 23 extending transversely at the lower zone of the back frame member 20 by means of straps 25, these straps defining the line of connection between the seat structure and the back structure. The rod 23 and thus'the lower part of the back frame member 20 and the line of connection between the seat structure and the back structure, is further connected to the support columns 13 of the base member 11 by restraining means such as two cords 26, one on each side of the chair.

In addition to the web 24, the seat and the back structures may be suited with a cover 28 and upolstery 29 enclosing the front end of the seat support 16 and the top of the frame member 20. The upolstery is suitably fitted with a thin central area 30 in both the seat structure and the back structure, thus forming ribs 31 at the borders. These ribs will act to support the user in transverse direction. The cover 28 may be stitched to the web 24 at the line of connection between the central area 30 and the rib 31 as shown at 32.

The legs 16A of the seat support 16 each carry a headed screw 27 which limits the forward movement of the adjoining slide 18 and thus the forward movement of the back structure.

On movement of the back structure by a user of the chair to adjust its inclination, the slides 17 and 18 will slide on the legs 16A of the seat support 16. The lower end zone of the frame member 20 is thereby guided in a substantially vertical plane by the cords 26 and the seat part of the web 24 through the straps 25. Thus, as it may be observed in FIG. 1, upon clockwise pivotal motion of the frame 20 about bolt 22, a leftward swing of the lower end zone of the frame 20 is prevented by the cord 26. Instead, the slide 18 will move rearwardly and, as a result, the lower end zone of the frame 20 will move substantially vertically in an upward direction. Conversely, upon counterclockwise pivotal motion of the frame 20 about bolt 22, a rightward swing of the lower end zone of the frame 20 is prevented by the strap 25. Instead, the slide 18 will move forwardly and,

as a result, the lower end zone of the frame will move substantially vertically in a downward direction. In raised position, the movement of the back structure is limited by the screw 27, whereby the seat structure will be somewhat lowered at the rearward part. In lowered position of the back structure, the rearward portion of the seat structure will be raised somewhat relative to a middle position. This corresponds well to the body movement of a user who enters the chair.

The laths 19 are also covered with upolstery 33 to provide armrests 34. These arm rests 34 will be moved together with the back part and thus be correctly located, independent of the position of the user.

The back structure is restricted in its rearward movement by the length of the cords 26. By using resilient cords 26 a progressively increasing force may be provided. By increasing the resiliency of the cords 26, the back structure may be rocked back and forth.

It has been found suitable to connect the cords 26 to the support columns 13 to extend substantially in horizontal direction when the rod 23 and the back frame 20 is in a middle position as illustrated in FIG. 1. The stop screw 27 may be placed to allow further forward movement of the back structure to make collapsing of the chair possible. It is however desirable to introduce a certain bias throughthe web 24 and the straps 25 to move the back structure back into a neutral position.

A series of modifications of the details described above may be introduced without departing from the scope of the invention. The seat and/or back structures may comprise rigid or semi-rigid structures, such as plates, or any other member suitable for carrying a person. The slides 17 and 18 may be formed in one piece and the arm rest 34 may be omitted.

In another embodiment of the invention, several, e.g. two or three chairs without armrests may be mounted side by side on a common base.

I claim:

1. In a chair or an analogous article of furniture, having a back structure and a seat structure which are hinged together to allow for an adjustment of the inclination of the back structure, and wherein the back structure is connected with slides which are carried by a substantially horizontal guide member on each side of the chair, the improvement comprising a supporting structure for maintaining stationary said seat structure at its front end and means for effecting a substantially vertical movement of the line of connection between the back structure and the seat structure when the inclination of the back structure is adjusted.

2. An article according to claim 1, wherein said guides extend from the front end of the seat structure.

3. An article according to claim 1, wherein the back structure has a lower part connected to a base member by a substantially horizontally extending cord member forming part of said means for effecting said substantially vertical movement.

4. An article according to claim 3, wherein the base member comprises a rod-shaped member on each side of the seat structure at approximately the same level as said seat structure, each said rod-shaped member constituting said guide member.

5. An article according to claim 4, wherein each said rod-shaped member is integrated with the front end of the seat structure for carrying said seat structure.

6. An article according to one of the claims I, wherein the seat structure and the back structure comprise a web which is suspended between a transverse member at the front end of the seat structure and a corresponding member at the top of the back structure.

7. An article according to claim 6, wherein the web is suspended between rod-shaped elements.

8. An article according to claim 1, wherein the back structure comprises a U-shaped member with downward extending legs connected to the slides.

9. An article according to claim 8, wherein said legs each have a portion that extends below the slides, the improvement further comprising a connecting means attached to the leg portions and to the supporting structure for limiting the movement of the back structure in the rearward direction.

10. An article according to claim 8, wherein the web is secured to a lower part of the U-shaped member.

11. An article according to claim 1, including arm rests carried between a pair of said slides on each side of said seat structure.

12. An article according to claim 9, wherein said connecting means is resilient to stretching.

13. An article according to claim 9, wherein said connecting means extends in a substantially horizontal direction when the back structure is in its middle position.

14. An article according to claim 1 wherein the seat and/or back structures comprise a rigid or semi-rigid support member for the user.

15. A chair comprising in combination:

a. a seat structure having front and rear ends;

b. a back structure including a generally vertically extending frame having an upper part and a lower part;

0. generally horizontal guide members extending on each side of the chair;

(1. a plurality of slides at least one mounted on each of said guide members;

e. pivot means connecting said frame to said slides for effecting adjustability of the inclination of said back structure, said pivot means dividing said frame into its said upper and lower parts;

f. means connected to said front end of said seat structure for maintaining stationary said seat structure at said front end;

g. hinge means connecting said rear end of said seat structure to a zone on said lower part of said frame for effecting a hinging movement between said seat structure and said back structure during adjustment of said inclination, said hinge means resisting a swinging motion of said zone in the one direction upon pivotal motion of said frame about said pivot means;

h. restraining means connected to said zone at the lower part of said frame, said restraining means resisting a swinging motion of said zone in the other direction upon pivotal motion of said frame about said pivot means; said hinge means and said restraining means effecting a substantially vertical movement of said zone upon adjustment of the inclination of the back structure. 

1. In a chair or an analogous article of furniture, having a back structure and a seat structure which are hinged together to allow for an adjustment of the inclination of the back structure, and wherein the back structure is connected with slides which are carried by a substantially horizontal guide member on each side of the chair, the improvement comprising a supporting structure for maintaining stationary said seat structure at its front end and means for effecting a substantially vertical movement of the line of connection between the back structure and the seat structure when the inclination of the back structure is adjusted.
 1. In a chair or an analogous article of furniture, having a back structure and a seat structure which are hinged together to allow for an adjustment of the inclination of the back structure, and wherein the back structure is connected with slides which are carried by a substantially horizontal guide member on each side of the chair, the improvement comprising a supporting structure for maintaining stationary said seat structure at its front end and means for effecting a substantially vertical movement of the line of connection between the back structure and the seat structure when the inclination of the back structure is adjusted.
 2. An article according to claim 1, wherein said guides extend from the front end of the seat structure.
 3. An article according to claim 1, wherein the back structure has a lower part connected to a base member by a substantially horizontally extending cord member forming part of said means for effecting said substantially vertical movement.
 4. An article according to claim 3, wherein the base member comprises a rod-shaped member on each side of the seat structure at approximately the same level as said seat structure, each said rod-shaped member constituting said guide member.
 5. An article according to claim 4, wherein each said rod-shaped member is integrated with the front end of the seat structure for carrying said seat structure.
 6. An article according to one of the claims 1, wherein the seat structure and the back structure comprise a web which is suspended between a transverse member at the front end of the seat structure and a corresponding member at the top of the back structure.
 7. An article according to claim 6, wherein the web is suspended between rod-shaped elements.
 8. An article according to claim 1, wherein the back structure comprises a U-shaped member with downward extending legs connected to the slides.
 9. An article according to claim 8, wherein said legs each have a portion that extends below the slides, the improvement further comprising a connecting means attached to the leg portions and to the supporting structure for limiting the movement of the back structure in the rearward direction.
 10. An article according to claim 8, wherein the web is secured to a lower part of the U-shaped member.
 11. An article according to claim 1, including arm rests carried between a pair of said slides on each side of said seat structure. Pg,9
 12. An article according to claim 9, wherein said connecting means is resilient to stretching.
 13. An article according to claim 9, wherein said connecting means extends in a substantially horizontal direction when the back structure is in its middle position.
 14. An article according to claim 1 wherein the seat and/or back structures comprise a rigid or semi-rigid support member for the user. 